IAEA-TECDOC-766 Safe handling, transport and storage of plutonium Proceedings of a Technical Committee meeting held in Vienna, 18-21 October 1993 INTERNATIONAL ATOMIC ENERGY AGENCY /A> October 1994
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FOREWORD Plutonium inventories and utilization rates worldwide are growing. It is important for nuclear power programmes everywhere that no incidents or accidents with plutonium occur.
In preparing this document EDITORIAL NOTE
CONTENTS Summary of the Technical Committee meeting.. Some safety aspects related to MOX fuel fabrication in Belgium... 11
SUMMARY OF THE TECHNICAL COMMITTEE MEETING INTRODUCTION The IAEA estimates that
Ongoing efforts with new processes and improved procedures continue to reduce radiation exposure. This
SOME SAFETY ASPECTS RELATED
TABLE II. TYPICAL ISOTOPIC COMPOSITIONS 0F Pu (w/o) Isotope A B (gas-graphite reactor) C (LWR) D (LWR) E (LWR recycled) Pu-238 0 0.05 0.5 1.5 2.3 Pu-239 94.0 79.0 43.1 58.5 48.6 Pu-240 5.45 17.0 4O.O 25.0 27.3 Pu-241 0.50 3.5 5.9 10.0 14.8 Pu-242 0.05 0.45 10.5 5.0 7.0 Taking into account
TABLE III. TYPICAL ISOTOPIC COMPOSITION Pu-238 1.2 ± 0.5 Pu239 61.1 ± 0.9 Pu-240 23.5 ± 1.2 Pu-241 8.8 ± 0.5 Pu-242 4.2 ± 0.5 Am-241 1.2 ± 0.4 the materials, due to the high temperature of the articles or packages and containers to be manipulated. On the other hand, the n-activity coming not only from spontaneous fissions, but also from alpha-n reactions with the oxygen present in the oxides, has increased, thus generating higher neutron dose rates. In order to protect the personnel, more shielding is necessary and special attention has to be paid to neutron dosimetry. From Tables II and III it can also be seen that the 241 Pu content is raised, giving a faster growth
Silo Dust collecting unit Vibrating tube Transfer
25 r VI 4\J J5 U 15 2.2* " 1 10 c o "3 ' n - ; / e _ ' / \ 1
18 17 16 IS E 14?- -S c c re - % 13 Ï" 12 10 y 10 15 Delivery nr. 20 25 30 FIG.
water-
SAFETY PRINCIPLES FOR PLUTONIUM FACILITIES IN FRANCE J.P. MERCIER Institut
French experience
protection from ionizing radiation
originate from
Furthermore, plutonium dioxide storage container drop tests have been carried out; these tests have made it possible to demonstrate that the container and its jacket remain leaktight after
4.2. Experience relating
5. CONCLUSION In France, the plutonium facilities in operation or under construction are relying on a very extensive experience accumulated over the past 35 years. Feedback is considered to be very important in the design, the surveillance and the control of the process, with a view to the continuous improvement of safety. Reduced average exposure of staff and reduced releases of liquid and gaseous effluent demonstrate the effectiveness of this safety feedback.
FRENCH ENGINEERING DESIGN RULES FOR SAFE HANDLING
In practice,
2.2. Ventilation The ventilation design will take into account
If a criticality accident may occur because of simultaneous occurrence of two anomalies, it must be shown that: the two anomalies are strictly independent,
3.1.3.2. Primary containment crossing operations Primary containment may be crossed or removed for: introducing material into process equipment and evacuating process products and byproduct
contamination monitoring of the exhaust air detection of radioactive material in the cooling or heating networks. Mechanical process equipment Mechanical process equipment or unwelded chemical equipment (containing liquid, gaseous or powder radioactive material) may have a limited tightness. Complementary devices (air current, etc.) will
that
To these ventilation families correspond ventilation networks with
Contamination hazard
Surface contamination control The alpha, beta/gamma emitting nuclides will
3.4.1. Provisions for design Provisions
Tanks with unsafe geometry
3.5.2.3. Hydrazine Reagent vessel containing hydrazine
no safety related incident has been reported; performances of process are very satisfactory; irradiation
OPERATIONAL SAFETY
conversion into Pu0 2 powder by oxalic precipitation and calcination in oxygen, conditioning the powder in packaged units then in welded cases and containers for interim storage, placing in transportation casks and plutonium shipping. These processing steps are accompanied by entry and exit accountancy statements, as well as contractual analyses of final product quality. Plutonium's physical properties (radioactivity, fission capacity, calorific strength, radiolysis
monitored continuously (activity, flow rate), for both main process ventilation stack and ventilation outlet of zones accessible to personnel. Also, non-stop monitoring
All classed workers on the Site are equipped with this case. The site's dosimetry laboratory
6. CONCLUSION Applying the principles developed above at La Hague enables production at the nominal throughput
SAFETY OF PLUTONIUM SHIPMENTS IN AND FROM FRANCE' C. RENARD, F. MATHIEU Institut de protection et de sûreté nucléaire, Fontenay-aux-Roses B. DESNOYERS Cogéma, Vélizy-Villacoublay P. MALESYS Transnucléaire Paris France Abstract Plutonium extracted from irradiated fuel at reprocessing plants is used in the manufacture of fresh fuel
Plutonium fuel production centres supplied with plutonium produced in France are located
For maritime shipment, France applies the International Maritime Dangerous Goods code (IMDG)
execution
For
AA-227 container AA-303 cartridge can SS5S5SH3
all
Orifice SECTION Orifice
Under these conditions, the maximum weight on the ground contributed by the cask is 1.1 t/m 2 in a vertical utilization position. Safety principles
Over FS-67
empty packaging loaded packaging 2
maximum weight
empty packaging
RD-26 packaging (Fig. FIG. 7. RD-26 packaging.
all gaskets of this containment are doubled in order to allow the checking of leaktightness after loading (testing
outer envelope. These layers are maintained by a steel framework including ISO standard corners for tie-down on trailer. At each end, the packaging is protected by 40 cm thick shock absorbing covers.
addition to these facilities, the SCPRI (Central Service for Protection against Ionizing Radiation}
CRITICALITY ACCIDENTS
The most obvious and significant characteristic of the criticality accidents that have occurred
(1) chemical form: uranyl nitrate solution (93%
2.9. LASL, Dec. 1949 When
3. DERIVATION OF A SIMPLIFIED MODEL TO ESTIMATE THE MAXIMUM TOTAL FISSION NUMBER
p add f 10" \ ) -X 5^^Sr^ JX_X T ö = 10 -u 5X 10-15 ZX 10-15 10' 10 5 10" Vs (cm3) Fig-1 Relation between reactivity
The following
figure are also shown the conventional evaluation curves obtained from other researchers' publications [7-9].
CIVIL PLUTONIUM HANDLING EXPERIENCE
8 5 3 6 2 -^-m f>
DIMENSIONS IN HM POS. DESIGNATION I 2 3 HEAD BEAM 4
CHLORINE POWDER OXIDES NaCJ-CsCl SALTS CHLORINATION IN MELT NaCl-CsCl REGENERATION SALT MELT CONCENTRACE (FOR STORAGE) OXIGEN4CHLORINE*ARGON ELECTROLISIS WASTE GASES GA:.SES SALTS
U-Pu OXIDE GRANULATED FUEL CLADDING ASSEMBLED WEIGHING OF EMPTY CLADDING MAKING FUEL PORTION FOR FE, CHARGING INTO CLADDING WEIGHING
WRAPPER WITH TAIL 1 BOX WITH 36 PERIPHERAL FE 3 BOXES WITH 91 CENTRAL FE MOUNTING
In general these goals were achieved. About 1 tonne of granulated fuel with Pu of different isotopic composition
BOR-60, BN-600 reactors
8. O.V.Skiba, Yu.P.Savochkin, A.V.Bychkov et al. Technology of Pyroelectrochemi- cal Reprocessing and Production
PLUTONIUM PRODUCTION AND STORAGE AT BNFL SELLAFIELD, UNITED KINGDOM B. LEIGH British Nuclear Fuels pic, Sellafield, Cumbria, United Kingdom Abstract Plutonium has been safely produced and stored at BNFL Sellafield for over 40 years. Although the basic chemical processes have not significantly changed throughout that time, the designs of
A decision was taken to replace the facility with a continuous process plant capable of operating until
interference fit stainless steel lid which was then welded using an overlapping resistance weld method. Proof testing
all air movement in the stores. Spare fan units and motors are also held separate from the store
conditions
2.4. The environment - disposal The regulation of matters involving the return of plutonium to the environment is the responsibility
Assessment Principles
expected that special training would
and
post-war weapons programmes when safety priorities were different to those expected now. De-commissioning of such facilities is fraught with difficulties, particularly when there is the possibility that old ventilation systems may be disturbed. It will often be necessary to re-engineer systems to modern standards before work can proceed.
Appendix 1 A TYPICAL LICENCE CONDITION 1. The licensee shall make and implement adequate arrangements for the periodic and systematic review
Appendix 2 LICENCE CONDITION OBJECTIVES CONDITION 1 INTERPRETATION The purpose
CONDITION
ensure that the licensee justifies safety during design, construction, manufacture, commissioning, operation,
CONDITION
CONDITION 32 ACCUMULATION OF RADIOACTIVE WASTE The purpose of this licence condition is to ensure that the production rate and accumulation
PLUTONIUM TRANSPORT: THE
In general the products of reprocessing, like irradiated fuel flasks require the most stringently designed packagings, plutonium requires packages which have
cylinder
transport package outers. It was recognised that these packages were therefore capable of sustaining much greater damage, even though it is clear that packages tested to the IAEA Regulations will ensure that the radiological consequences of the majority of potential accidents will
package and designed and constructed a 4500 te target of steel and reinforced concrete. A special track was built, enabling the prototypes to be carried by a rocket-powered sled. Following a successful side-on impact at the prescribed speed at full scale, the package was then subjected to the rest of the NRC criteria of crush, punch and slash tests, fire and immersion, and BNFL are satisfied with the results so far. Further development has been suspended because of the uncertainties in the final regulatory position regarding these shipments although it is worth noting ACTRAM's comment "the NRC tests were likely to prove unduly severe,
During road transports
(total radiation from plutonium for example is in the order of two thirds neutrons and one third gamma),
by BNFL does take pride in its enviable safety record for the transportation of plutonium
LIST
Leigh,